linux-kernel - Re: [PATCH v16 04/14] mm/damon: Adaptively adjust regions

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <1592472218-22708-1-git-send-email-foersleo@amazon.com>
Date:   Thu, 18 Jun 2020 11:23:38 +0200
From:   Leonard Foerster <foersleo@...zon.com>
To:     SeongJae Park <sjpark@...zon.com>
Cc:     akpm@...ux-foundation.org, SeongJae Park <sjpark@...zon.de>,
        Jonathan.Cameron@...wei.com, aarcange@...hat.com, acme@...nel.org,
        alexander.shishkin@...ux.intel.com, amit@...nel.org,
        benh@...nel.crashing.org, brendan.d.gregg@...il.com,
        brendanhiggins@...gle.com, cai@....pw, colin.king@...onical.com,
        corbet@....net, dwmw@...zon.com, foersleo@...zon.de,
        irogers@...gle.com, jolsa@...hat.com, kirill@...temov.name,
        mark.rutland@....com, mgorman@...e.de, minchan@...nel.org,
        mingo@...hat.com, namhyung@...nel.org, peterz@...radead.org,
        rdunlap@...radead.org, riel@...riel.com, rientjes@...gle.com,
        rostedt@...dmis.org, sblbir@...zon.com, shakeelb@...gle.com,
        shuah@...nel.org, sj38.park@...il.com, snu@...zon.de,
        vbabka@...e.cz, vdavydov.dev@...il.com, yang.shi@...ux.alibaba.com,
        ying.huang@...el.com, david@...hat.com, linux-damon@...zon.com,
        linux-mm@...ck.org, linux-doc@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v16 04/14] mm/damon: Adaptively adjust regions

On 2020-06-15T18:19:17+02:00 SeongJae Park <sjpark@...zon.com> wrote:

> From: SeongJae Park <sjpark@...zon.de>
> 
> Even somehow the initial monitoring target regions are well constructed
> to fulfill the assumption (pages in same region have similar access
> frequencies), the data access pattern can be dynamically changed.  This
> will result in low monitoring quality.  To keep the assumption as much
> as possible, DAMON adaptively merges and splits each region.
> 
> For each ``aggregation interval``, it compares the access frequencies of
> adjacent regions and merges those if the frequency difference is small.
> Then, after it reports and clears the aggregated access frequency of
> each region, it splits each region into two or third regions of random
> size, if the total number of regions after the splits wouldn't exceed
> the user-specified maximum number of regions.
> 
> In this way, DAMON provides its best-effort quality and minimal overhead
> while keeping the overhead bound.
> 
> Signed-off-by: SeongJae Park <sjpark@...zon.de>
> ---

Reviewed-by: Leonard Foerster <foersleo@...zon.de>